The New World That iPS Cells Will Bring

A stem cell champion was crowned last month. Dr. Takahashi from the RIKEN center in Japan received the prestigious Ogawa-Yamanaka Prize for developing a human iPS cell therapy to treat a debilitating eye disease called macular degeneration. We wrote about the event held at the Gladstone Institutes in a previous blog and saved the juicy insights from Dr. Takahashi’s scientific presentation and her CIRM-exclusive interview for today. We also put together a two minute video (see below) based on the interview with her as well as with Dr. Deepak Srivastava, Director of the Gladstone Institute of Cardiovascular Disease and Mr. Hiro Ogawa, a co-founder of the Ogawa-Yamanaka Prize.

Dawn of iPS Cells

As part of the ceremony, Dr. Takahashi gave a scientific talk on the “new world that iPS cells will bring”. She began with a historical overview of stem cell research, starting with embryonic stem cells and the immune rejection and ethical issues associated with their use. She then discussed Dr. Yamanaka’s game-changing discovery of iPS cells, which offered new strategies for disease modeling and potential treatments that avoid some of the issues can complicate embryonic stem cells.

Her excitement over this discovery was palpable as she explained how she immediately jumped into the iPS cell field and got her hands dirty. Knowing that this technology could have huge implications for regenerative medicine and the development of stem cell therapies, she made herself a seemingly unattainable promise. “I said to myself, I will apply iPS cells to humans within five years. And I became a woman of her words.”

An iPS cell world

Dr. Takahashi went on to tell her success story, and why she chose to develop an iPS cell therapy to treat a disease of blindess, age-related macular degeneration (AMD). She explained how AMD is a serious unmet medical need. The current treatment involves injections of an antibody that blocks the activity of a growth factor called VEGF. This factor causes an overgrowth of blood vessels in the eye, which does major damage to the cells in the retina and can cause blindness. This therapy however, is only useful for some forms of AMD not all.

Dr. Masayo Takahashi describing her team’s iPS-based therapy for macular degeneration during the inaugural ceremony for the Ogawa-Yamanaka Prize at The Gladstone Institutes.

She believed she could fix this problem by developing an iPS cell technology that would replace lost cells in the eye in AMD patients. To a captivated crowd, she described how she was able to generate a sheet of human iPS derived cells called retinal pigment epithelial (RPE) cells from a patient with AMD. This sheet was transplanted into the eye of the patient in the first ever iPS cell clinical trial. The transplant was successful and the patient had no adverse effects to the treatment.

While the clinical trial is currently on hold, Dr. Takahashi explained that she and her team learned a lot from this experience. They are currently pursuing additional safety measures for their iPS cell technology to make sure that the stem cell transplants will not cause cancer or other bad outcomes in humans.

Autologous vs. Allogeneic?

Another main topic in her speech, was the choice between using autologous (iPS cells made from a patient and transplanted back into the same patient) and allogeneic (iPS cells made from a donor and then transplanted into a patient) iPS cells for transplantation in humans. Dr. Tahakashi’s opinion was that autologous would be ideal, but not scaleable due to high costs and the amount of time it would take to make iPS cell lines for individual patients.

Her solution is to use an arsenal of allogeneic iPS cells that can be transplanted into patients without rejection by the immune system. This may be possible if both the donor and the patient share the same combination (called a “haplotype”) of cell surface proteins on their immune cells called human leukocyte antigens (HLA). She highlighted the work ongoing in Japan to generate a stock of HLA haplotype matched iPS cell lines that could be used for most of the Japanese population.

Changing the regulatory landscape in Japan

It was clear from her talk that her prize winning accomplishments didn’t happen without a lot of blood, sweat, and tears both at the bench and in the regulatory arena. In a CIRM exclusive interview, Dr. Takahashi further explained how her pioneering efforts to bring iPS cells to patients helped revolutionize the regulatory landscape in Japan to make it faster and easier to test iPS cells in the clinic.

“The power of iPS cells changed the Japanese [regulatory] law dramatically. We made a new chapter for regenerative medicine in pharmaceutical law. With that law, the steps are very quick for cell therapy. In the new chapter [of the law] … conditional approval will be given if you prove the safety of the cell [therapy]. It’s very difficult to show the efficacy completely in a statistical manner for regenerative medicine. So the law says we don’t have to prove the efficacy [of the therapy] thoroughly with thousands of patients. Only a small number of patients are needed for the conditional approval. That’s the big difference.”

We were curious about Dr. Takahashi’s involvement in getting these regulatory changes to pass, and learned that she played a significant role on the academic side to convince the Japanese ministry to change the laws.

“This law was made in the cooperation with the ministry and academia. That was one thing that had never happened before. Academia means mainly the Japanese society for the regenerative medicine, and I’m a committee member of that. So we talked about the ideal law for regenerative medicine, and our society suggested various points to the ministry. And to our surprise, the ministry accepted almost all of the points and included them into the law. That was wonderful. Usually we are very conservative and slow in changing, but this time, I was amazed how quickly the law has been changed. It’s the power of iPS cells.”

The iPS cell future is now

As a champion stem cell scientist and a leader in regenerative medicine, Dr. Takahashi took the opportunity at the end of the event to emphasize that all scientists and clinicians in the iPS cell therapy field need to consider three things: develop safe protocols for generating iPS cells that become standard practice, understand the patient’s needs by focusing on how to benefit patients the most, and think of iPS cells as a treatment and consider the risk when developing these therapies.

The new world of iPS cells is opening doors onto uncharted territory, but Dr. Takahashi’s wise words provide a solid roadmap for the future success of iPS cell therapies.